This invention relates generally to the manufacture and configuration of bottles, in particular, thin walled plastic bottles of generally parallelepiped configuration. In such bottles, particularly those having generally flat sides, there has long been a problem of the sides bowing outwardly, not only under the static pressure of the liquids contained within, but also in the event of either freezing of the liquid contained therein, or in the event of the fully loaded model being dropped.
In some prior art bottles, such as that disclosed in my U.S. Pat. No. D355,854, and in Platte, Sr. U.S. Pat. No. 4,969,922, additional stiffness and support for the sidewall is provided by reentrant beams molded into and extending inwardly of the sidewall in mutually opposed relationships and bonded together in the center of the bottle. While this has provided additional stiffness, it has been found that such fixed, bonded reentrant beams, when subjected to the pressures of freezing liquid within the bottle or a fully loaded bottle being dropped, may fracture, thus losing the stiffness and potentially causing leakage in the bottle.
In order to overcome the deficiencies of the prior art, this invention provides a molded plastic bottle of generally parallelepiped configuration having two opposed sides, a top with an opening, a bottom and two ends, with at least one of the two opposing sides having integrally molded therewithin a reentrant beam support extending inwardly of the bottle and engaging the other such opposing side to provide support against deflection of the opposing sides relative to one another. This support includes a first portion adjoining that one side of the bottle and being of generally cylindrical configuration, with an annular, flexible portion joining that cylindrical portion to a support extremity of a smaller cross section than the first portion. That support extremity engages the other opposing side of the bottle, whereby the flexible portion of the support permits a limited amount of deflection of the two opposing sides toward or away from one another, while restraining excessive such movement.